/*
This file is a part of MonaSolutions Copyright 2017
mathieu.poux[a]gmail.com
jammetthomas[a]gmail.com

This program is free software: you can redistribute it and/or
modify it under the terms of the the Mozilla Public License v2.0.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Mozilla Public License v. 2.0 received along this program for more
details (or else see http://mozilla.org/MPL/2.0/).

*/

#include "Base/Crypto.h"

using namespace std;

namespace Base {

#if OPENSSL_VERSION_NUMBER < 0x10100000L
static HMAC_CTX* HMAC_CTX_new() {
	HMAC_CTX* ctx = new HMAC_CTX();
	HMAC_CTX_init(ctx);
	return ctx;
}
static void HMAC_CTX_free(HMAC_CTX* ctx) {
	HMAC_CTX_cleanup(ctx);
	delete ctx;
}
#define EVP_MD_CTX_new  EVP_MD_CTX_create
#define EVP_MD_CTX_free EVP_MD_CTX_destroy
#endif

UInt8  Crypto::Rotate8(UInt8 value) {
	value = ((value >> 1) & 0x5555) | ((value & 0x5555) << 1);
	value = ((value >> 2) & 0x3333) | ((value & 0x3333) << 2);
	return (value >> 4) | (value << 4);
}
UInt16 Crypto::Rotate16(UInt16 value) {
	value = ((value >> 1) & 0x5555) | ((value & 0x5555) << 1);
	value = ((value >> 2) & 0x3333) | ((value & 0x3333) << 2);
	value = ((value >> 4) & 0x0F0F) | ((value & 0x0F0F) << 4);
	return (value >> 8) | (value << 8);
}
UInt32 Crypto::Rotate24(UInt32 value) {
	value = ((value >> 1) & 0x00555555) | ((value & 0x00555555) << 1);
	value = ((value >> 2) & 0x00333333) | ((value & 0x00333333) << 2);
	value = ((value >> 4) & 0x000F0F0F) | ((value & 0x000F0F0F) << 4);
	return Byte::Flip24(value);
}
UInt32 Crypto::Rotate32(UInt32 value) {
	value = ((value >> 1) & 0x55555555) | ((value & 0x55555555) << 1); // swap odd and even bits
	value = ((value >> 2) & 0x33333333) | ((value & 0x33333333) << 2); // swap consecutive pairs
	value = ((value >> 4) & 0x0F0F0F0F) | ((value & 0x0F0F0F0F) << 4); // swap nibbles ... 
	value = ((value >> 8) & 0x00FF00FF) | ((value & 0x00FF00FF) << 8); // swap bytes
	return (value >> 16) | (value << 16); // swap 2-byte long pairs
}
UInt64 Crypto::Rotate64(UInt64 value) {
	value = ((value >> 1) & 0x5555555555555555) | ((value & 0x5555555555555555) << 1);
	value = ((value >> 2) & 0x3333333333333333) | ((value & 0x3333333333333333) << 2);
	value = ((value >> 4) & 0x0F0F0F0F0F0F0F0F) | ((value & 0x0F0F0F0F0F0F0F0F) << 4);
	value = ((value >> 8) & 0x00FF00FF00FF00FF) | ((value & 0x00FF00FF00FF00FF) << 8);
	value = ((value >> 16) & 0x0000FFFF0000FFFF) | ((value & 0x0000FFFF0000FFFF) << 16);
	return (value >> 32) | (value << 32);
}

UInt8* Crypto::Hash::Compute(const EVP_MD* evp, const void* data, size_t size, UInt8* value) {
	thread_local struct CTX {
		CTX() : _ctx(EVP_MD_CTX_new()) {}
		~CTX() { EVP_MD_CTX_free(_ctx); }
		EVP_MD_CTX*	operator&() { return _ctx; }
	private:
		EVP_MD_CTX* _ctx;
	} CTX;
	EVP_DigestInit_ex(&CTX, evp, NULL);
	EVP_DigestUpdate(&CTX, data, size);
	EVP_DigestFinal_ex(&CTX, value, NULL);
	return value;
}

UInt8* Crypto::HMAC::Compute(const EVP_MD* evp, const void* key, int keySize, const void* data, size_t size, UInt8* value) {
	thread_local struct CTX {
		CTX() : _ctx(HMAC_CTX_new()) {}
		~CTX() { HMAC_CTX_free(_ctx); }
		HMAC_CTX* operator&() { return _ctx; }
	private:
		HMAC_CTX* _ctx;
	} CTX;
	HMAC_Init_ex(&CTX, key, keySize, evp, NULL);
	HMAC_Update(&CTX, BIN data, size);
	HMAC_Final(&CTX, value, NULL);
	return value;
}

UInt16 Crypto::ComputeChecksum(BinaryReader& reader) {
	UInt32 sum = 0;
	UInt32 pos(reader.position());
	while(reader.available()>0)
		sum += reader.available()==1 ? reader.read8() : reader.read16();
	reader.reset(pos);

  /* add back carry outs from top 16 bits to low 16 bits */
  sum = (sum >> 16) + (sum & 0xffff);     /* add hi 16 to low 16 */
  sum += (sum >> 16);                     /* add carry */
  return ~sum; /* truncate to 16 bits */
}


UInt32 Crypto::ComputeCRC32(const UInt8* data, UInt32 size, ROTATE_OPTIONS options) {
	static const UInt32 CRC32[256] = {
	   0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
	   0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
	   0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
	   0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
	   0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
	   0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
	   0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
	   0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
	   0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
	   0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
	   0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
	   0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
	   0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
	   0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
	   0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
	   0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
	   0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
	   0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
	   0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
	   0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
	   0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
	   0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
	   0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
	   0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
	   0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
	   0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
	   0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
	   0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
	   0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
	   0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
	   0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
	   0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
	   0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
	   0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
	   0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
	   0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
	   0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
	   0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
	   0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
	   0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
	   0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
	   0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
	   0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
	};

    UInt32 crc(0xffffffff);
	for (UInt32 i = 0; i < size; ++i) {
		if (options&ROTATE_INPUT)
			crc = (crc << 8) ^ CRC32[(crc >> 24) ^ Rotate8(*data++)];
		else
			crc = (crc << 8) ^ CRC32[(crc >> 24) ^ *data++];
	}
    return options&ROTATE_OUTPUT ? Rotate32(crc) : crc;
}


} // namespace Base
